Field of the Invention
This invention relates to a flexible carrier for carrying a plurality of containers manufactured using a rotary die.
Description of Prior Art
Conventional container carriers are often used to unitize a plurality of similarly sized containers, such as cans, bottles, jars and boxes and/or similar containers that require unitization. Flexible plastic ring carriers are one such conventional container carrier.
Flexible plastic ring carriers having a plurality of container receiving apertures that each engage a corresponding container may be used to unitize groups of four, six, eight, twelve or other suitable groups of containers into a convenient multipackage.
Typically, flexible ring carriers are manufactured in a generally continuous string by feeding an extruded sheet of plastic material, such as low density polyethylene through a vertically reciprocating punch press. As a result, traditional presses punch discrete rows of carriers in which each carrier is connected to adjacent carriers within a row. Depending on the size of the carrier being formed, and the width of the web of carrier material, a plurality of rows may be formed simultaneously in the web of material. To minimize problems associated with indexing variation as the web of material passes through the punch press, adjacent rows of carriers have been punched spaced from each other. As the web passes out of the punch press, the carriers are provided in discrete rows, and are subsequently wound onto separate supply reels or spools or fan folded into boxes.
Marketing demands have tended toward the packaging of more containers in a single package. As a result, there is a demand for larger carriers, such as, for example, twelve-pack carriers in which two arrays of six container receiving apertures are provided on each side of a central web. Even with relatively small containers, a two row twelve-pack carrier of this type is significantly long.
In addition, marketing demands have driven a need for printed container carriers. The printing process has traditionally introduced an added complication into the manufacture of container carriers as the printing often required careful indexing of the punched carrier to print in the proper region of the carrier or has required careful indexing of the punching process to produce container carrier in exact overlay corresponding to printed sheet.
For speed and efficiency in manufacture, it is common to punch at least one entire carrier with each stroke of the press, and index the web forward by at least one carrier length in preparation for the next stroke. As the length of the carriers increases, the indexing stroke increases, and errors in indexing are magnified. An additional problem is that the punched rows of carriers can “wander” exiting the punch press, resulting in misalignment of the unpunched portion of the web, and malformation of portions in subsequent carriers punched in the web.
As can be appreciated, the location, size and shape of the container receiving apertures for holding the containers are critical to proper functioning of the carrier. An undersized, oversized, wrongly located, or malformed container receiving aperture may inadequately retain a container, allowing the container to fall from the carrier. Failure of a carrier in the automatic machinery attaching a carrier to the containers can cause significant difficulties, and significantly curtail output. Failure during transport of the assembled package, at best, is inconvenient
As partially described above, punch presses have speed limitations, are noisy, require costly dies, require sophisticated indexing and are limited in the shapes that can be punched at high speeds. There is therefore a need for an alternative method of manufacture for such plastic ring carriers.